Radio frequency antennas are often designed as arrays to provide sufficient gain. Types of omni-directional antennas include series fed arrays, co-linear coaxial (COCO) antenna, and the like. The power feed network associated with antenna arrays, however, is often complex. For example, linear arrays typically use a distributed feed network/power divider for the power feed. This type of power feed network is complex because antenna pattern and gain depend on physical and network parameters making it very difficult to achieve correct phase and amplitude to get maximum gain on azimuth and minimize side lobes. Some physical parameters include the number of elements and their spacing. Some feed network parameters include the phase and amplitude of the power signal at each of the antenna feeds as well as the impedance of the feed network delivering the power. Moreover, array antennas of this type are frequently not readily scalable, are difficult to manufacture, are fragile, and are limited in performance by the accumulation of manufacturing errors in the individual components.
Thus, it would be desirous to provide an omni-directional antenna that had lower errors, was less fragile, and had increased scalability, but retained all the advantages of the simple COCO antenna and removed some of its disadvantages, such as, for example, the requirement to reverse the inner and outer conductor of a coaxial transmission line and it's fixed driving point impedance, which generally requires a matching network.